Sludge pumping assembly



May 27, 1 c. R. JOHNSON swncs PUMPING ASSEMBLY 2 Sheets-Sheet 2 FiledNov. 25, 1953 swoon PUMPING ASSEMBLY Carl Roy lohnson, Chicago, 111.,assignor to Yeomans Brothers Company, Melrose Park, I1l., a corporationof Delaware Application November 25, 1953, Serial No. 394,264

2 Claims. ((11. 103-45) The present invention is directed to an improvedapparatus for handling materials such as sludge and industrial wastes ofdifferent natures which are difficult to pump efiiciently.

Numerous difierent arrangements are currently in use for the purpose ofpumping sludge suspensions at various concentrations. Each has its ownadvantages and its disadvantages. From the standpoint of operatingefficiency, one of the best of these arrangements is a pneumatic ejectorof the type which consists of a closed receiver provided with checkvalves on the inlet and in the discharge lines, a control valve mountedon the receiver and a pair of open bells suspended in the receiver andmovable in response to the liquid level in the receiver to operate thecontrol valve. The control valve, in turn, actuates a piston valve whichoperates to introduce and to terminate the flow of compressed air intothe receiver during the discharge cycle.

This type of pneumatic ejector is very efiicient in operation andrequires little maintenance. However, the unit is expensive to installand is somewhat expensive to operate because of the necessity ofproviding high pressure air. Moreover, ejectors of this type operate bya gravity feed and must be located so that the inlet to the ejector islower than the discharge point for the sludge being received. Normally,this necessitates providing a special chamber or other enclosingstructure located below the floor level of the building in which theejector unit is installed. Such enclosures add materially to the cost ofthe installation and makes the unit relatively inaccessible for purposesof lubrication and whatever maintenance that may be required.

In strictly mechanical systems for handling sludges, it is common toemploy positive displacement sludge pumps of the plunger type in whichthe fluid is pumped by the reciprocating action of a piston typeplunger. Normally, the pistons of such pumps are driven by means of aneccentric connected to a positively driven shaft. The drive means andthe eccentric are coupled together by means of a shear pin whichprovides some degree of protection against excessive stresses in thedrive mechanism. Pumps of this type are essentially constant speedmechanisms, with only the stroke of the plunger being capable ofadjustment and that to only a limited extent. Further, when the plungerdisplacement is to be changed it requires shutting down the pump andrealigning the eccentric with respect to the driven shaft. Thisprocedure is, of course, time consuming and incapable of fine adjustmentof the stroke of the plunger except by continuous trial and error.

An even more serious objection to the eccentric drive, plunger typesludge pump arises from the fact that the motion of the plunger is notstrictly an up and down motion but has a lateral component which createsexcessive wear on the packing of the cylinder. Additionally, these pumpsare subject to considerable vibration during use, as a result of thereciprocation of the plunger, and

head 27. Thus, as the plunger reaches theupper end Patented May 27, 1958ice pumps do not completely satisfy the requirements of the art, andthere is a continuing need for an improved pump mechanism for handlingsludge and sludge type materials which is efficient in operation andinexpensive to maintain and to install. The provision of such a pumpmechanism is the principal object of the present invention.

Another object of the invention is to provide an improved pump mechanismparticularly adaptable to handling sludge and sludge type products undersuch conditions that the rate of discharge of the pump can be readilyand continuously varied during the operation of the pump, withoutshutting down the unit.

Still another object of the invention is to provide a drive mechanismfor sludge pumps which eliminates the numerous gear assemblies ofexisting drive units and thereby eliminates the objectionable noise andrelatively high expense of such gear assemblies.

An illustrative embodiment of the invention is illustrated in theaccompanying drawings where:

Figure 1 is a somewhat schematic view in elevation of a complete pumpmechanism in accordance with the invention, and

Figure 2 is an enlarged View in elevation and partly in cross sectionillustrating certain natures of the pump mechanism shown more fully inFigure 1.

The pump mechanism illustrated in Figures 1 and 2 includes a pumpcylinder or receiver generally indicated at numeral 10 in which aplunger 11 is arranged to reciprocate. The cylinder 10 is relieved toaccommodate a. stufling box gland 12 and a plurality of packing rings 13(Figure 2).

The sludge or other material to be pumped is introduced into themechanism through an inlet line 14, the flow through the line 14 beinggoverned by a ball valve element 16 arranged to be seated on a removablevalve seat ring 17. On the upstroke of the plunger the sludge enteringthe inlet line 14 unseats the ball element 16 and passes into thepumping chamber 18 where on the downstroke it is acted upon by the recirocatory movement of the plunger 11. The sludge then under pressure isforced through an outlet line 19, and unseats the outlet valve member 20which normally rests in seated relation on a removable valve seat ring21. The inflow valve is, of course, closed at this time. The pumpedsludge is conducted away from the pump mechanism through an outlet line22;

The plunger, in the illustrated mechanism, has a gen erally hollowinterior and is provided with a centrally disposed cylindrical shaft 23.The upper end of the shaft 23 is received within a fluid tight casing 24and has a piston head 27 arranged to move in the casing 24 in responseto fluid pressure in the casing 24. in the position of the mechanismshown in Figure 2, the plunger 11 is at the bottom of its stroke and isarranged to move upwardly upon the introduction of a pressure fluid suchas oil into an inlet conduit 28 which communicates with the casing 24.As the hydraulic fluid under pressure is introduced into the conduit 28,it acts against the piston head 27 on the shaft 23 and forces the pistonand hence the plunger 11 upwardly.

A second conduit 2? is connected to the casing 24 at a point above thelimit of travel of the piston head 27, and like the conduit 28 isdesigned to admit hydraulic fluid to the casing 24- or to convey fluidfrom that casing depending on the direction of movement of the piston'voir 34. p a As shown in Figure 1, the'port46 of'the reversing valve 40is connected to the'line 2S? o f'the hydraulic rarnasslembly and the'port 47 is connected to the line 28. Hence, by operation of thereversing valve, fluid is alternately V p 3. of its stroke, hydraulicfluid is V duit 29 and simultaneously drained from the conduit 28'sothat the fluid acting from the top of the piston head 27 causes theplunger to reverse its direction and commence its downwardls'trolteSimilarly, in theupward stroke, when fluid is being introduced into theconduit 28, the fluid remaining in the casing 24 is being drainedthrough the conduit 29 by 'a control system subsequently to bedescribed. The casing 24 and the piston head 2'7, thereby provide ahydraulic ram mechaintroduced into the counisjrn for controlling thereciprocating movement or" the discharge line 32 forthe-purpose ofpreventing the pressur'e'in the line from reaching too high a value. Ifthe pressure is below a certain predetermined safe value, the fluidpasses directly through the relief valve 35, but if the pressure exceedsthe predetermined value, at least To obtain the fullest realization ofthe advantages of some of the fluid is shunted back into the reservoir34 7 through a line 37. The discharge line 32 is in continu ous fluidcornmunication by Way oi line 38, with an inlet 39' of a reversing valve49, and also with a port'41 on atwo-way pilot valve 42 1 The reversingvalve 40 may consist of a casing in which a sliding plunger with portsprovided therein is free toslide in response to changesi'n'fiuidpressu're at opposite. ends of the slide. drawings; thereversing valve has a pair of oppositely spaced ports 43' and 44 whichreceive the hydraulic fluid to act againstene .or the other end of theslide contained in the casing, and a pair of outlet ports 46 and 47which alternately cornmuriicatejwith the inlet port 39 throughthe portsin the slide, depending upon'the position of the slide in the reversingvalve casing. Another outlet or exhaust port 43 is provided along with aconduit 49m drain fluid from whichever port 46 or 7- is not beingsupplied introduced "underpressure into the line ,28 from the port-47 tomove the plunger 11' upwardly, and in the next half cycle, the pressurefluid is introduced through the line29 into the port 46 to reverse themovementof the plunger 11.

t The operation of the reversing valve 40is controlled by the pilotvalve 42 which determines'into which end-of the valve 40 the hydraulicfluid is introduced. The pilotvalve 42 includes four ports, the first ofwhich, '41, is

in constant fluid communication with the pump 31. A'

second port 51 and an associated conduit 52 serve to. drain thehydraulic fluid from the pilot, valve'bac'k into; the reservoir. 34 asindicated-by the arrows. A,-pair of ports 53 and 54 are, alternatelyconnected through the valve to theinlet port 41 and function tointroduce the reversing valve 40. v 7

Therate of deceleration or acceleration at the ends (Sf the plungerstroke are very conveniently controlled by providing a pair ofadjustable speed control throttling the hydraulic'fluid. alternatelyinto ports 4:3 or 44 of 'va1vesf56 and 5-7 in the, lines 58 andf 5 9whieh' connect the ports 54, and 53. with the ports 44 and 43,respective 71y, tofregulate the an ountof hydraulic fluid entering thereversin'g'valve 40'fro mithe 'pilot'valve42.

in; the type of valve shown in "the with the pressurefluid back into thereser- The speed of the plunger is governed by the setting on a bypassvalve 61 located in the line 62 which con meets the discharge line 32 tothe reservoir 34. The position of the valve 61 is adjustable to vary theamount of fluid available to actuate the hydraulic. control system byreturning continuously predetermined amounts of the fluid back to thereservoir. By this means a uniform output pump 31 can be used to drivethe sludge pump at varying speeds.

The pilot valve 42 is operated by a ii-shaped control member 63 which isarranged to be engaged by an operating dog 64 carried on a shaft 66. ofthe control member 63 from: one position 'to its other position changesthe flow of fluid through the pilot valve 42 in the mannerpreviously'described', to thereby control the operation of the reversingvalve 40.;

In the drawings, the plunger ll is shown in its lower-V most position.As'the plungermoves. into this position, the pilot valve 42 is moved tocause the oilor other hydraulic fluid to pass from the port 41' into theport 54, 7 through the valve'56, and into the'port 44 of the reversingvalve 40. When this happens, the pressure'at the end'of the slidecontained in the reversing valvef40 causes, the slide to move from rightto left. As theslide shiits,

it establishes communication between the inlet line 38 I and the port 47to introduce fluid underrpressure into thelower end of the hydraulic ramassembly. and thereby force the piston'hejad 27 upwardly. At the'sanietime the postiofln' of'th'e, pilot valve 4211is such that the por t 5 3is open to the drain port 51 so that fluid fromgthe' opposite end of thereversing valve 4% at the port 43,

can drain back into the reservoir 34 through the con;

duit 52; .In this position, the drain port 48 of the reversing valve isopen to port 46' of the same valve thereby permitting "the hydraulicfluid from the upper part of; the hydraulic ram to be drained" throughthe line 29 and the line 49 back into the-reservoir 34; 7

As the plunger 11 approaches the upper end of its stroke. the dog 64*engages the control member. 63"a.n'd

movesit't'o theidotted. line position shown in Figure 1. In

' this position-off the valve, thepo'rt 4?; is in communifcation withport5'3so that fluid under pressure is introduced throughth'e valve 57int o'the port 43 and into the reversingvalye ,dllfThe slide ofthereversing valve'40 then shifts to the right in response to thischange in pressurev and the inlet line 38 is then connectedthroughtheslide i with theport 46 and 'theline 29. At the same time,

the drain port 48 is;inr fluid communication with the port 47 s'o tha'tas 'thehydraulic fluid exerts its pressure onth'e top of the piston head2 7{the hydraulic fluid at the base of the hydraulicramis drainedthrough the line 28 and, the line 49 back into the reservoir 34.Similarly, in this- 'po sition the-port"54 of thepilot' valve I 42 isconnected to the drain port 51 so that hydraulic fluid isdrained-fromthe port 440i the reversing'valve assembly.

Thiscompletes thecycle offoper'ation. V The. present invention providesa very convenient means for adjusting boththestroke andspeed ofplunger-1 type"punipsin a manner not: previously possible withconventional sludgepu-mps; One of the important'advantagesofthe-assemblyis' the fact that the plunger is operated inastrictly'up and downmotionWithout substantial' "side thruston the'plunger elementswhichfwou-ldcreate'undu'e'wear on the-packing. This absence of lateralzthrust caused byi'the. plunger movement is also responsibleforthesubstantial decrease in mechanical vibration.'accomPl ished by pumps ofthe present invention. V j V r The capability'of thepresent assembly tobe accurately adjusted; over aywide speed-range makes it preferable toother; types of; pumps, eyenjthose employing an ex-. pensive variablespeed drive because the means for ary n he p d n he p e en emb y s cdera ly simpler and less cap'able of mechanical damage. V F It will beevident that; various modifications can madetd the structure of theabove-described assembly The movement 2,8 without departing from thescope of the present invention.

I claim:

1. A sludge pumping system comprising a receiver including an inlet, anoutlet, and a plunger slidable within said receiver to eflect an intakeof material through said inlet and a discharge of such material throughsaid outlet, a ram or" the double acting type including a cylinder, apiston slidable within said cylinder, and a piston rod extending fromsaid cylinder and inter-connected with said plunger, a constant deliveryfluid pump, a reservoir supplying fluid to said pump, and means foradjustably controlling the operation of said plunger including apressure relief valve, a by-pass valve, a reversing valve, a pilotvalve, a pair of flow regulating valves, and means associated with saidplunger for actuating said pilot valve and for controlling the length ofstroke of said plunger, said reversing valve having individualcommunication with said pump, said reservoir, and with each of the endsof said piston whereby a first pressure fluid flow may be alternatelydirected from said pump through said reversing valve to one end and thento the other end of said piston and whereby a simultaneous withdrawal ofpressure fluid may be afforded from the opposing end of said pistonthrough said reversing valve to said reservoir, said by-pass valve andsaid pressure relief valve being intermediate of said pump and saidreversing valve whereby the speed of the stroke of said plunger may becontrolled and whereby overload protection may be secured, said pilotvalve having individual communication with said pump, said reservoir,and with each of the ends of said reversing valve whereby, throughcooperation of said pilot valve actuating means, a second pressure fluidflow is alternately directed from said pump through said pilot valve toone end and then to the other end of said reversing valve and asimultaneous withdrawal of pressure fluid is afforded from the opposingend of said reversing valve through said pilot valve to said reservoir,said second pressure fluid flow and said simultaneous withdrawal ofpressure fluid from said reversing valve eflecting reciprocation of saidplunger by causing said first pressure fluid flow to be alternatelydirected to one end and then the other of said piston and by affordingsimultaneous withdrawal of pressure fluid from the opposing end of saidpiston, said second pressure fluid flow and said withdrawal of pressurefluid between said pilot valve and said reversing valve each beingthrough said flow regulating valves for cushioning the ends of thestroke of said plunger by controlling the acceleration and decelerationthereof.

2. A motor means including a ram of the double acting type, a pressuresource, and means for controlling the operation of said ram, said ramcomprising a cylinder,

a piston slidable within said cylinder, and a piston rod extending fromsaid cylinder, said control means comprising a by-pass valve, a pressurerelief valve, a revers ing valve, a pilot valve, a pair of flowregulation valves, and means associated with said piston rod foractuating said pilot valve and for controlling the length of the strokeof said piston, said reversing valve having individual communicationwith said pressure source, said reservoir, and with each of the ends ofsaid piston Whereby a first pressure fluid, flow may be alternatelydirected from said pressure source through said reversing valve to oneend and then to the other end of said piston and whereby a simultaneouswithdrawal of pressure fluid may be afforded from the opposing end ofsaid piston through said reversing valve to said reservoir, said by-passvalve and said pressure relief valve being intermediate of said pressuresource and said reversing valve whereby the speed of the stroke of saidpiston may be controlled and whereby overload protection may be secured,said pilot valve having individual communication with said pressuresource, said reservoir, and with each of the ends of said reversingvalve, whereby, through cooperation of said pilot valve actuating means,a second pressure fluid flow is alternately directed from said pressuresource through said pilot valve to one end and then to the other end ofsaid reversing valve and a simultaneous withdrawal of pressure fluid isafforded from the opposing end of said reversing valve through saidpilot valve to said reservoir, said second pressure fluid flow and saidsimultaneous withdrawal of pressure fluid from said reversing valveeflecting reciprocation of said piston by causing said first pressurefluid flow to be alternately directed to one end and then to the otherend of said piston and by affording simultaneous withdrawal of pressurefluid from the opposing end of said piston, said second pressure fluidflow and said Withdrawal of pressure fluid between said pilot valve andsaid reversing valve each being through said flow regulating valves forcushioning the ends of the stroke of said piston by controlling theacceleration and deceleration thereof.

References Cited in the file of this patent UNITED STATES PATENTS968,263 Quinn Aug. 23, 1910 1,910,766 Hobson May 23, 1933 2,056,204Noack Oct. 4, 1936 2,168,711 Kyle Aug. 8, 1939 2,236,665 Beers Apr. 1,1941 2,304,131 Vickers Dec. 8, 1942 2,363,389 Brice Nov. 21, 19442,413,029 McFarland Dec. 24, 1946 2,414,979 Ross Jan. 28, 1947 swim)STATES PATENT ()FFICE CERTIFICATE 0F CGRRECTION Patent No. 2,836,122 May27, 1958 Carl Roy Johnson It is hereby certified that error appears inthe printed specificatio of the above numbered patent requiringcorrection and that the said Letter Patent should read as correctedbelow.

Column 4, line 16, after "reversing valve 40.," insert the followingparagraph:

The shaft 66 in turn is secured to the inside of the hollow plunger 11as best illustrated in Figure 2 of the drawings. The actuating mechanismshown in the drawings is a simple example of the types of mechanismswhich can be employed to accomplish the same purpose, The mechanism canbe replaced, for example, by a pair of limit switches which are actuatedby the movement of the plunger and which can be used to operate asolenoid to shift the control member 63 from one position to the other.Numerous other mechanisms for accomplishing this function will suggestthemselves to those skilled in the art The particular actuatingmechanism illustrated in the drawings has the advantage that the strokeof the plunger may be very simply adjusted merely by positioning the dog64 at the desired location along the shaft 66.

Signed and sealed this 21st day of October 1958,

(SEAL) Attest:

B f AXLINE ROBERT 0., WATSON Attestlng Officer Cbn'missioner of Patents

